Mary Szela Appointed CEO, Dr. Eugene Sun as EVP, Research and
Development, Michael Kenston as Chief Commercial Officer and Dr. Thomas
Koestler as Chairman of the Board

April 03, 2013 10:58 AM Eastern Daylight Time

NEW HAVEN, Conn.--(BUSINESS WIRE)--Rib-X
Pharmaceuticals, Inc. announced today new appointments to the
executive team and Board of Directors. Mary Szela has been appointed as
Chief Executive Officer, bringing 25 years of experience as an
accomplished pharmaceutical executive to the Company. Eugene Sun, M.D.,
has been appointed Executive Vice President, Research and Development,
bringing clinical and scientific leadership and expertise to the
Company. Michael Kenston has been appointed Chief Commercial Officer,
bringing a broad range of commercial, sales and business development
experience to the Company. Rib-X also announced today that director,
Thomas Koestler, Ph.D., has been appointed Chairman of the Board. Ms.
Szela, who joined the Company’s Board in January, will remain a director.

Commenting on these appointments, Kevin Ferro, CEO of Vatera Holdings
LLC, said, “The experience and expertise that Mary, Eugene, Mike and Tom
bring to Rib-X is impressive and represents a new beginning for the
Company. We are committed to ensuring that the novel and much needed
antibiotics being developed by a dedicated team of scientists at Rib-X
are appropriately resourced and brought to patients as soon as possible.”

"Rib-X is a highly energized biopharmaceutical company developing the
right products at the right time,” commented Ms. Szela. “Never has there
been more of a need for novel drugs to combat the proliferation of
resistant pathogens emerging worldwide. Rib-X has an exciting broad
spectrum antibiotic poised to enter multiple pivotal studies as well as
a discovery platform based on Nobel Prize-winning science that utilizes
unprecedented structural insights to target the vulnerabilities of
pathogens.”

“Mary brings to Rib-X the leadership, product development and commercial
experience to build Rib-X into a leading specialty pharmaceutical
company delivering important new anti-infective agents to clinicians and
patients,” commented Dr. Koestler.

With more than two decades in senior roles at Abbott Laboratories (now
AbbVie), Ms. Szela most recently served as Senior Vice President, Global
Strategic Marketing and Services of the Pharmaceutical Products Group.
Previously, she served as Senior Vice President of U.S. Pharmaceuticals,
an $8 billion business. For over seven years, she directed the
development, launch and growth of eight new pharmaceutical products,
including leadership of AbbVie’s flagship product, Humira.

Prior to 2001, Ms. Szela held a series of senior positions in Abbott’s
hospital products division where she was responsible for the
peri-operative, intensive care and pain management pharmaceutical
business, the global One-2-One outsourcing business, the critical care
device business and the vascular medicine pharmaceutical business.

Dr. Sun joins Rib-X following 17 years at Abbott Laboratories (now
AbbVie), where he most recently served as Corporate Vice President,
Global Pharmaceutical Clinical Development. In this role, Dr. Sun was
responsible for global clinical development, medical affairs, and
clinical operations for all pipeline compounds and marketed products
across the pharmaceutical portfolio. Prior to 2005, he held increasingly
senior leadership positions in the R&D organization. During his tenure
at Abbott, Dr. Sun oversaw the development and approval of multiple
indications for Humira, and also led the development and worldwide
regulatory approval of the landmark HIV protease inhibitor Kaletra.

From 2001 to 2007, Dr. Sun served as the industry representative on the
Antiviral Drugs Advisory Committee of the Food and Drug Administration.
Dr. Sun received his undergraduate degree from Harvard University, his
M.D. from New York University School of Medicine, and completed his
residency in Internal Medicine and fellowship in Infectious Diseases at
the University of California, San Francisco.

“Dr. Sun has a unique ability to translate science into commercial
understanding and success,” said Ms. Szela. “Dr. Sun’s extensive
clinical and global regulatory experience across multiple therapeutic
areas made him an invaluable asset at Abbott where I had the privilege
of working with him for over ten years, and he will be instrumental to
Rib-X as we continue the clinical development of our pipeline and move
towards approval and commercialization.”

Ms. Szela continued, “Delafloxacin represents an incredible opportunity
to address the high unmet medical need for better anti-infectives across
multiple indications in both IV and oral formulations. Mike brings over
20 years of commercial experience and a diverse skillset to help Rib-X
successfully execute the commercial strategy for this promising
candidate as well as for our broader pipeline.”

Mr. Kenston joins Rib-X with over 20 years of commercial, sales and
business development experience. He most recently served as Vice
President, Commercial Analysis at Reata Pharmaceuticals where he led
marketing research, forecasting and SG&A optimization for the pre-launch
of Bardoxolone Methyl. Prior to Reata, Mr. Kenston was Vice President,
Commercial Analysis and Business Development Search & Evaluation for
Lundbeck, Inc. (formerly Ovation Pharmaceuticals). Mr. Kenston played an
instrumental role in the sale of Ovation to Lundbeck and continued on to
lead the core commercial analysis processes for the company. Mr. Kenston
held several commercial roles over 16 years at Abbott Laboratories (now
AbbVie), including Director level positions in promotional analytics and
marketing research and assessment. While at Abbott, Mr. Kenston also
served as Product Manager for the adult respiratory segment of the
antibiotic Biaxin.

Mr. Kenston has a Bachelor of Science degree from Northern Illinois
University and received his MBA in finance from Indiana University.

Dr. Koestler, an Executive Director of Vatera Holdings LLC, joined the
Rib-X Board in 2012. In his nearly 30-year career in the pharmaceutical
industry, Dr. Koestler established a track record of building
high-performance teams that drove global success in research and
development. Most recently, he served as Executive Vice President of
Schering-Plough Corporation and President of Schering-Plough Research
Institute (SPRI), the pharmaceutical Research and Development arm of
Schering-Plough Corporation. Under his leadership, the company developed
an industry-leading pipeline that contributed to the turnaround of the
business. Dr. Koestler’s accomplishments include over 80 product
approvals including over 30 New Molecular Entities/BLAs. Before joining
Schering-Plough, Dr. Koestler was Senior Vice President and Head of
Global Regulatory Affairs for Pharmacia Corporation. Prior to joining
Pharmacia, he was Senior Vice President and Global Head, Drug Regulatory
Affairs, Compliance Assurance, Clinical Safety and Epidemiology for
Novartis. Before that appointment, he was Senior Director, Drug
Regulatory Affairs, at Ortho McNeil and a Director of Regulatory Affairs
at Bristol-Myers Squibb, Westwood Pharmaceuticals.

Dr. Koestler is also a member of the Board of Directors of Novo Nordisk
A/S, Momenta Pharmaceuticals Inc., Pearl Therapeutics Inc., ImmusanT
Inc., and Arisaph Pharmaceuticals Inc. Dr. Koestler also chairs the
Scientific Advisory Board of Bausch & Lomb. Dr. Koestler has a Bachelor
of Science, Biology, from Daemen College and a Ph.D. in Medicine &
Pathology from the Roswell Park Memorial Institute.

About Rib-X:

Rib-X
Pharmaceuticals, Inc. is a biopharmaceutical company developing new
antibiotics to provide superior coverage, safety and convenience for the
treatment of serious and life-threatening infections. The Company's
proprietary drug discovery platform is based on Nobel Prize-winning
science and provides an atomic-level, three-dimensional understanding of
interactions between drug candidates and their bacterial targets and
enables design of antibiotics with enhanced characteristics. Rib-X’s
lead program is Delafloxacin, an enhanced spectrum IV/oral antibiotic
intended for use as first-line monotherapy to treat multiple bacterial
diseases, which recently completed a Phase 2b clinical trial for the
treatment of acute bacterial skin and skin structure infections. The
Company's pipeline also includes its preclinical RX-04 program and other
discovery stage anti-infective programs. Rib-X is privately held and
backed among others by Vatera Healthcare and Warburg Pincus. For more
information, please visit www.rib-x.com.